Senior Dreamworld supervisors will this week give evidence in the coronial inquest into how four people died at Australia's largest theme park.

Key points

Members of the maintenance team are set to give evidence

Dreamworld's general manager of park operations Troy Margetts is the last person listed to give evidence

Lawyers will question senior supervisors over previous breakdowns of the rapids ride

The inquiry into the deaths of Cindy Low, Kate Goodchild, Luke Dorsett and Roozi Araghi resumes today, nearly two years after they were fatally crushed on the Thunder River Rapids ride.

Ms Low's son Kieran, and Ms Goodchild's daughter Ebony, were also on the ride and survived.

A fortnight of hearings were held in June and shed some light on the Gold Coast tragedy, with evidence of operator confusion, unclear emergency plans and an under-resourced safety unit.

The ABC understands lawyers representing families of the victims are eager to probe Dreamworld's "on-site boss" Troy Margetts. The general manager of park operations will give evidence at the end of next week.

Another key witness, former Dreamworld employee Stephen Buss, is due to appear tomorrow.

It is understood Mr Buss was involved in a 2014 incident, where a raft on the Thunder River Rapids ride collided, but no one was injured.

Less than two years later, in October 2016, Ms Low, Ms Goodchild, Mr Dorsett and Mr Araghi were killed instantly when their six-person raft collided with an empty vessel and flipped backwards.

The victims' lawyers are expected to use Mr Buss' account of the 2014 incident when they probe Dreamworld senior management later in the inquest.

There will also be scrutiny over how the theme park's management responded to the earlier incident and attempts to establish what, if anything, was learnt from it.

In June, barrister Steven Whybrow, who is representing the father of siblings Kate Goodchild and Luke Dorsett and Ms Goodchild's partner, told the court the 2014 event was "an almost identical incident of rafts coming into contact" after a pump had gone off.

Dreamworld's owners say a recent audit of the theme park's rides and slides found they were safety compliant.

Parent company Ardent Leisure says Workplace Health and Safety Queensland did not issue any improvement notices during last month's audit or the previous inspections in 2017.

"[The inquest] will be a difficult time for many and our hearts and thoughts firmly remain with the families and all those affected by this tragedy," Ardent Leisure chair Gary Weiss said in a statement.

What have we already learnt about the fatal accident?

The inquest has already been told the Thunder River Rapids ride had broken down twice on the day four people were killed and a young ride operator did not know there was an emergency stop button within her reach.

There were previous collisions and incidents on the ride in 2001, 2004, 2005, 2014 and 2016.

On the day of the fatal incident, a large pump on the ride failed at 11.50am and 1:09pm without any incidents.

On Tuesday, junior engineer Ged Cruz is expected to give evidence, along with control room operator Nigel Irwin, former Dreamworld employee Stephen Buss and safety officer John Clark.

First aid officer Ben Hicks and safety officer Rebecca Ramsey are scheduled to appear on Wednesday.

In the second week of the hearing, engineering supervisors Wayne Cox and Scott Ritchie are expected to be asked why the Thunder River Rapids ride was not shut down after two breakdowns on the day of the deadly incident.

Dreamworld's general manager of park operations Troy Margetts is the last person listed to give evidence in this round of hearings.

It will be the first time the inquest has heard from the most senior managers at Dreamworld.